Process of treating aluminous ores.



- .H. A. RICHMOND PROCESS OF TREATING ALUMINOUS ORES.

APPLICATION FILED NOV. 21. 1916.

1,245,383. Patented Nov. 6, 1917.

nwntoz STATES PATENT OFFICE.

HAROLD A. BIOHIOID, OI PBOVIDEIO I,-BHODE ISLAND, ASSIGNOB 'IO GENERAL ABRASIVE comm, mo, 01 NIAGARA FALLS, mw YORK, A CORPORATION 0! new YODK P300188 0] TREATING ALIJHINOUS ORES.

Specification 0! Letters Patent.

Patented Nov. 6, 191 '7.

Application filed November 27, 1918. Serial No. 188,55i.

To all whom it may concern:

Be it known that I, HAROLD A. Rrcnmonn, 4

a citizen of the United States, and resident of the city of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Processes of Treating Aluminous ores, of which the following is a specification. I

This invention relates to an improved process of treating aluminous ores and more particularly. those containing a large percentage of-silica.

In ractice the process heretofore employed for the p ose of treating aluminous ores required e use of an ore such as bauxite which is high. in iron and low in silica in order to form ma etic ferrosilicon, whereby these objectionab e properties could be readily removed; but the production of such ores, particularly in this country, is limited in quantity, in fact the bauxites found here do not contain sufiicient iron in proportion to their silica content to make a magnetic ferrosilicon when fused, without the additionwfiron to the. charge.

The French bauxites are much higher in iron and are, therefore much more readily reduced by the old method, but these bauxites are difiicult to obtain and are very expensive.

There are, however, among other aluminous ores, large deposits of kaolin found in this country, which may be reduced in a practical way by the employment of my imtained from such materials possesses greater purity and from which a material of superior commercial quality is produced.

' A still further object of the invention is,.. 'that by my improved process the cost of production is materially lessened as the ore is reduced by the application of heat of a lower temperature and exposed to the heat for a shorter period.

With these and other objects in view, the invention consists of certain novel features, as will-be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawing.

The figure illustrated in the drawing is a sectional side elevation showing one form of furnace by the use of which my improved process may be successfully carried out.

As-is well known aluminous ores occur widely disseminated in nature but in pract cally all occurrences the ores contain be- 81(168 the alumina, the oxids of silicon, iron and titanium, either separately or together.

In order to obtain the alumina in a high degree of purity either for the manufacture of aluminum or for abrasive or refractory purposes 1t is important that these impurities be removed so that a substantially pure alumina results therefrom.

It has been the custom to reduce the impurities to elemental form and thus remove them from the unreduced alumina.

Usually it is sought to make the alloy resultmg from the reduction of the impurities high in iron so that it will be magnetic and if the impurities in the aluminous ore, are not of such a character as to yield an alloy high in iron suflicient oxid of iron is added to bring this about.

For example there are large deposits of kaolin found in this country which may be successfully used by my improved process as a source of alumina. If these were to be employed as raw material in the familiar rocess above referred to, the reaction would 0 as indicated by the following chemical equation:

As will be seen from this equation there is required a very large amount of energy to bring about its reduction and as a consequence it has heretofore been the custom to select ores containing a lower percentage of silica or a higher percentage of iron.

I have discovered that by smelting the aluminous ores with carbonaceous material and sulfur or the sulfid of a base metalliferous element that I can efiect the elimination of the silica in a satisfactory and economical manner.

I will illustrate my invention with reference to the treating of kaolin and as the basic metalliferous sulfid I will use pyrites or iron sulfid.

I take by weight, 182 parts of kaolin, 120 gains of pyrites and 24 parts of carbon. see are intimately mixed together by suitable means and then placed in an electric furnace, one form of which is illustrated in the accompanying drawing. The mixture is subjected to, electrically developed heat by passing a powerful current through the electrodes 10 and 11, whereby the passage of the current from'one to the other forms an are at 12 which fuses the material, the molten alumina being shown at 13 and the separated and settled molten iron at 14 which may in some cases be drawn oif through the tap hole 15. By the application of the heat a reaction takes place which may be expressed by the following equation.

furnace or by the use of magnets.

If it is desired to use sulfur the reaction takes place according to the following equation:

' Al,O +SiS +2CO and there results an aluminous product substantially free from impurities.

A study of reaction No; 1 compared with reactions No. 2-and No. 3 shows that there is required a much greater quantity of thermal energy per unit of alumina than in the two latter reactions and moreover we can obtain an elimination of the silica impossible to effect by reaction No. 1.

' The metal produced as in equation No. 2 is always very high in iron. In conse-'- quence it settles out very perfectly from the fused alumina .as indicated at 14 in the drawing when it may be readily drawn 01f and so removed through the tap hole 15.

I do not wish to be restricted to the use of my improved process to the reduction of kaolin as this process may be employed for reducing any aluminous ore to which it may be adapted.

Having thus described one illustrative embodiment of my invention, and the best. mode known to me for carrying out my method, I desire it to be understood that although specific terms are employed, they are used in a specific and descriptive sense and not for purposes of limitation, the scope of the invention being defined and limited only by the appended claims.

I claim: N

1. The process of forming crystalline alumina, which consists in mixing carbonaceous material and the sulfid of a basic element with aluminous ore, subjecting the mixture to electrically developed heat. and separating the resulting basic element and. the crystalline material.

2. The process of refining aluminous ores which consists in mixing carbonaceous material and a sulfid with aluminous ore, subjecting the same to electrically developed heat, and removing the impurities as gaseous sulfid.

3. The process of refining aluminous ores which consistsin' mixing carbonaceous material and a sulfid with aluminous ore, subjecting the same to electrically developed heat, and removing the impurities as gaseous sulfid and metal.

4. The process of forming crystalline alumina which consists in mixing carbonaceous material and sulfur with aluminous ore, subjecting the mixture to electrically developed I heat, and removing the resulting sulfurous compounds and crystalline material separately.

5. The process of refining aluminous ores I which consists in mixing carbonaceous matemal and sulfur with the ore, smelting the mixture with electrically developed heat and removing the impurities as ga'seous sulfid.

6. The process of refining aluminous ores which consists in mixing carbonaceous mate'- rial and-sulfid with the ore, subjecting the mixture to electrically developed heat, and removing the impurities as gaseous sulfid and reduced metal.

7. The process of forming crystalline alumina which consists in mixing carbonaceous material and sulfur with aluminous ore, subjectingthe mixture to electrically developed heat, and separating the resulting crystalline material and reduced metal.

- '8. The process of refining aluminous ores which consists in mixing carbonaceous material and the sulfid of a basic metal with the ore, subjecting the mixture to electrically developed heat, cooling the resulting product, and separating the crystalline material and reduced metal.

9. The process of refining aluminous ores which consists in mixing carbonaceous material and the sulfid of a basic metal with the ore, subjecting the mixture to electrically developed heat, removing the resulting reduced metal in the molten condition, and cooling the product.

In testimony whereof I affix my signature in presence of a witness.

HAROLD A. RICHMOND.

' Witness:

HOWARD E. BARBER. 

